Engineering a Critical Valve & Control System Upgrade in FCC Operations
In preparation for one of its largest turnarounds, a major client in the petrochemical sector selected Contec to deliver several critical upgrade projects, including the replacement of two large Slide Valves (SVs) and their Hydraulic Control Units (HCUs) within a Fluid Catalytic Cracking Unit (FCCU).
The existing systems had become unreliable and obsolete. Failure could result in unit trips, safety risks, or production losses. The challenge was to complete the upgrade within a narrow turnaround window and limited space, while ensuring full compliance with safety standards and SIL requirements.
Through close coordination with the client’s process, mechanical, piping, instrumentation, and electrical teams, Contec delivered a complete engineering solution, from concept to construction package.
Key Outcomes:
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SIL-compliant design with multiple redundancy layers
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Emergency Shutdown (ESD) functionality with <5s closure
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Integration of new HCU and SVC systems with DCS and MCC
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Cable routing, interconnection, and loop drawings for installation
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On-time delivery of a complete construction package
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FAT preparation and QA/QC documentation for execution phase
The challenge
Mitigating Obsolescence and Safety Risks During a High-Pressure Turnaround
The original slide valves and hydraulic control units no longer met operational or safety expectations. The engineering team faced a tight schedule, limited access space, and the need to coordinate across multiple disciplines, all while preparing for seamless startup after replacement.
Our approach
Multidisciplinary Engineering for a High-Stakes Equipment Replacement
Concept & FEED Phase
We worked closely with the client to define functional requirements, battery limits, and process integration points. Budget estimates supported funding requests and covered materials, programming, and owner’s costs.
Detailed Engineering
- Requisition package for slide valves and HCUs, including:
- SIL-compliant safety logic and 2oo3 solenoid ESD configuration
- Redundant CPUs, pumps, and power supplies
- Fire-resistant hydraulic fluid and ATEX Zone 1 compliance
- Diagnostic feedback and Lock-In-Place (LIP) safety logic
- Thermal mitigation strategies via low-speed motors and shielding
- Construction package for E&I contractor:
- Cable block diagrams, loop drawings, and revised P&IDs
- Cable tray layouts and interconnection to MCC, DCS, and SCADA
- Updated Cause & Effect matrix and software flags for programming
- SIL calculations, cable sizing, and selectivity studies
- Vendor evaluation and clarification meetings
- Preparation of FAT checklists and QA/QC deliverables
Thanks to close collaboration with all stakeholders, Contec delivered a high-quality engineering package on time, setting the stage for a safe, successful execution during turnaround and a reliable restart of the FCCU.
